In Cisco Unity Connection, a user uses an Integrated Messaging Access Protocol client, such as ViewMail, to record, send, and forward voice messages to another user. Which system feature is used to map the sender and the recipient of the message to the correct user?
A. message notification
B. greetings and caller input
C. mailbox storage settings and administration
D. Simple Mail Transfer Protocol proxy address
E. distribution lists
F. external service accounts
